A computer can make hundreds of calculations in three or four minutes but men can't.It can compose music,draw pictures.play chess,write poetry and sometimes find the right boys for the right girls.The police use them to get the information (data) about crimes and traffic.But computers cannot function alone.A computer must have three people:the programmer,the operator and the technician.First,the programmer prepares the programmer,then,the operator presses the right buttons,and finally the technician services the computer and repairs it when it breaks down.